Clamping chuck



Jan. 5 1926.

' 1,568,869- H. BOES CLAMPIN `CHUCK Filed March 28, 1925 Patented `lan.5, 1926.

HEINRICH reas. 0F 3.01m .G-EeMeNY.

@Alarme GHUQK- Application filed March 28, 19 25 Serial No. 19,161.

To all whom t mrijz/ concern.' Be it known that I, HEIN on Bons, a citi`zen of the German VRepublic, and resident of Bonn,Rosentalv StreetlpGerinany, have invented a new Iand useful improved Clamping-Chuck (forwhichl have tiled an application iiiGeiaiiany, Feb. G, 1192i), of'whichthe :following :is a specification.

'My invention relates to a clamping chuck intended for use especially inconnection with drills `and the like, and being distinguished withrespect to the known chucks in which rradially movable clamping cheeksare ,moved inwards and outwards by `a .ro- :tatory sleeve adapted to be.turned upon a `mandrel extending .through this sleeve by the vfactsthat the clamping cheeks 1project :laterally .out of the mandrel-slotshaving .saidcheelrs arranged within them, .and that .the sleeve-chamberenclosing these parts hat' an annularsloping bottom-face, and that an-annulus vclosing ythe vsieeve.-cliarnber at its :front-end has acorrespondingly.sloping inner face which contacts with thefront `facesoffthe projecting cheek-parts, `whose rear kfaces Contact with .said.slopingbottoni-face, ofthe sleeve-chamber, the y arrangement beingsuchthat :the clamping cheeks are actuated, i. ve.

V.moved radially,.as Awellfas axially, by turnling :the sleeve, the:said :sloping faces .transn'iitting the i motion to the cheeks, asis.more :fully describedfliereinafter. n

f My invention is illust-rated j Idiagrannnati callyuand `bycway ofexamplein the accom- ,pan in g crawing inwhich- Figure 'l is a side viewofthe complete clinch;

Figure 2 is in its lower part an axial section through the chuck, theradially adjustable clamping. cheeks, (d) thereof assuming their innerposition, and the mandrel (u) being shown in side view, as in Fig. l;

Figure 3 is an illustration similar to Fig. 2, but the clamping cheeksbeing shown in their outer position, and the mandrel being turned 900relatively to Figs. l and 2;

Figure 4t is a rear view of Fig. l, seen in the direction from themandrel to the adjusting sleeve (b) Figure 5 is a horizontal sectionthrough the chuck;

Figure 6 is a frontal View of the chuck, i. e. seen in the directionfrom the frontal face of the adjusting sleeve to the mandrel;

Figure 7 is a side view of the front end of the mandrel;

Figure 8 is an axial section through the front end of the. mandrel;

Figure 9 is a perspective view of one of .the (three) clamping cheeks,drawn to an enlarged scale relatively to the other figures, and :beingseen inthe direction from its flat narrow outer face to `the'wedge-shaped, Fig. 10) .inner face; and

`Figure l() is an illustration similar to Figure 9, the clamping vcheekbeing seen in ythe direction from its wedge-.shaped inner 'lv-.ce to its(flat narrow, Fig. 9) outer face.

The chuck consists of two main members which are the `mandrel or, moreprecisely, holding mandrel u. ,and .the adjusting sleeve @the ,rear endof which is threaded .internally and screwed `upon an external thread uofftheinandrel a; the chuck consists, fu r .ther of ,three clampingcheeks `al which are ,located in three radially disposed slots dprovided ,in the front endof theinandrel, i. e. that end which`isjylocated in the front half of Ithe sleeve o and l.enclosed by it.`The slots al areof rhomboidal sha-pe; they converge towards theffrontalface o of the man drel where they communicate with one another and withan opening provided in that" faceo vfor,thereception ofthe wdrill or thelike, asappe'ars ,from Fig. 8.

' lilaofh..slotjolcontains,a clamping check cl', lthe particular; shapeof which 'appears especially from 9l and ,10Q The vradial length of thechecks d fisgreater than the radial length pr deptlrof the slots alsothat 1 each cheekfprojects beyond the vouter end of theappertainingzslot. The projectingl` part of `A`eachcheek .formsa foot,d3 `at its front iendlwith..which ithabuts on an annulusb2 @secured'inQthe :front end'of thesleeve b. y.The 3inner .diameterof the sleeve,is large enough to ireceive said projecting parts of the clampingcheeks, and the bottom of the sleeve-chamber forms a sloping circularshoulder o with which contact the correspondingly sloping inner endfaces [Z2 of the clamping cheeks al, as appears from Figs. 2 and 3. -Theend-faces d2 can slide radially upon said sloping circular shoulder o',and the frontal faces of the feet d3 can slide upon the slightly conicalinner face of the annulus b2, the Obliquity of which corresponde,exactly to that of the said face o. Figs. 2 and 3 show the two extremepositions of the clamping cheeks d in that in Fig. 2 the wedgeshapedinner edges thereof contact, or Contact nearly, with one another (thefeet cl3 contacting at their inner faces with the circumferentialsurface of the inandrel a), and in Fig. 3 the itat narrow outer faces ofthe cheeks contact, or contact nearly, with the inner circumferentialwall of the sleeve Z1, i. e. with the chamber in the front part thereof.

The clamping cheeks can be moved into, and out of, the slots (l of themandrel a by turning the sleeve b upon the mandrel wherebyv the sleeveis moved axially upon the mandrel by means of the threads of both parts.Two of the possible relative positions of these parts are shown in Figs2 and 3; those two positions are, in fact, the two extreme orend-positions, corresponding to the extreme positions of the clampingcheeks, as already mentioned. `Villien the sleeve b is in the positionshown in Fig. 2, and is being turned, the annulus b2 presses against thefrontal faces of the feet Z3 of the cheeks, and moves them, i. e., ofcourse, not merely said feet, but the entire cheeks, axially, but owingto the rhomboidal configuration of the slots (Z of the mandrel a, aswell as to the corresponding configuration of the clamping cheeks, theselatter are moved also radially whereby the wedge-shaped clamping facesarc separated from one another so as to provide the space necessary forthe reception of the drill or other tool to be clamped fast by and inthe chuck.

rFhe position of the clamping cheeks in Figs. 5 and (3 corresponds totheir position in Fig. 2.

The position of the mandrel in Fig. e corresponds to its position inFigs. l and 2.

The annulus b2 is affixed in the sleeve Z) by screws e, Fig. 5, but, ofcourse, any other suitable fastening means may be used instead of saidscrews.

The sleeve b is roughened on its circumferential outer surface so thatit can be `grasped firmly and turned easily.

lThe degree of Obliquity of the sloping fares of the clamping cheeks andof the corresponding faces of the slots (l is such that the drill orother tool clamped fast by and in the chuck can be retained in placesolely by the sleeve, that is to say, without the assistance of acounter-nut or any equivalent thereof. The respective tool is held fast,firmly and reliably, even when subjected to great stress.

I claim:

A clampingchuck for drills and the like comprising in combination, amandrel having radial slots formed in the tool receiving end thereof,each of said slots having their upper and lower faces converging and ar-'anged in parallelism, an adjusting sleeve rotatably engaged over andadjustable with respect to said mandrel having an internal annularchamber therein,the upper end of said chamber being downwardly andoutwardly inclined and the lower end of the chamber being open, anannulus engaged in the open lower end of the sleeve closing the lowerportion of said internal chamber, the inner face of such annulus beingdownwardly and out wardly inclined and arranged parallel to the upperend of said internal chamber, clamping checks correspondingly shaped tosaid slots received in the same and movable therein, the upper and lowerfaces of these cheeks being slidably engaged with the adjacent faces ofthe slots and arranged in parallelism thereto, the upper end portions ofsaid cheeks being extended laterally from the slots and formed withoblique faces slidably engageable with and parallel to the upper end ofthe annular chamber, and laterally positioned longitudinally extendingfeet on the outer sides of each of said cheeks arranged beyond andwithout the outer sides of said slots and received in portions of theinternal annular chamber in the adjusting sleeve, the outer ends of eachof said feet being obliquely formed and arranged parallel to theinclined surface of the inner side of said annulus and being slidablyengage able thereover.

In witness whereof l have hereunto set my l'ia'nd.

H El N RICH BOES.

